1. Field of the Invention
The present invention relates to an apparatus for recording and replaying real-time information such as video data and audio data and a method of controlling such an apparatus.
2. Description of the Related Art
As multi-channel information providing has been implemented through the widespread use of community antenna televisions or cable televisions (CATV) and so on, the demand has been increasing for simultaneously reproducing a plurality of audio and video items from a single information recording and replaying apparatus, in contrast to a related-art video cassette recorder (VCR). In order to satisfy the demand, an apparatus called audio-video server (AV server) has been available that records and replays audio and video data (AV data), using a recording and replaying medium that allows random access such as a hard disk.
In a video server used in a broadcast station, for example, superimposing a still-frame image for explanation called telop on a material (AV data) previously recorded is generally performed. Such a telop is generally an image made up of a combination of characters and graphics and usually produced through a computer graphics (CG) producing function retained by a personal computer or a workstation and the like.
An apparatus having such a CG producing function (a CG producing apparatus) usually creates a CG image, using a graphics command. The graphics command is generally made up of data for designating a type of character or graphic to draw and data for designating the size and position on the screen and so on of the image. The amount of data making up one CG image is therefore very small.
However, a related-art AV server has a configuration for manipulating a moving image provided in real time, which is incapable of manipulating control commands such as a graphics command described above and text data. Consequently, in order to superimpose a CG image on an AV material stored in such an AV server, a graphics command is executed in a CG producing apparatus different from the AV server so as to expand the command to dot-by-dot CG image data of one frame. The CG image data is stored in the CG producing apparatus or an external storage and the data is transferred to the AV server when necessary.
However, when the CG image data in a drawn form is sent to the AV server as described above, the CG producing apparatus or the external storage requires a relatively large amount of storage although the data amount of the original graphics command is very small. This is because the data amount of the CG image data to which the graphics command is expanded is much greater than that of the original graphics command and comparable to a moving image.
It takes extremely long transmission time to transfer such a large amount of data from the CG producing apparatus to the AV server through a network, for example, which may be a factor that affects smooth and rapid processing.
In the related-art technique it is required that a graphics command is executed in a CG producing apparatus different from the AV server so as to expand the command to CG image data, and the CG image data is stored in the CG producing apparatus or an external storage. As a result, a heavy load is applied to the personal computer and the like as the CG producing apparatus. It is inconvenient for the user as well that the operation is complicated.
It is a first object of the invention to provide an information recording and replaying apparatus and a method of controlling the same for manipulating information provided in real time and the other kind of information in a unified manner. It is a second object of the invention to provide an information recording and replaying apparatus and a method of controlling the same for increasing the speed of processing of the system as a whole without any additional large-capacity storage medium when the processing is performed for superimposing a kind of material on another kind of material provided in real time.
An information recording and replaying apparatus of the invention comprises: a first information recording and replaying means for performing at least one of an operation of recording a first type of information provided in real time on a storage means for storing information and an operation of replaying the first type of information from the storage means; and a second information recording and replaying means for performing at least one of an operation of recording a second type of information other than the first type of information on the storage means and an operation of replaying the second type of information from the storage means. The second information recording and replaying means may be capable of performing input and output of information in a form suitable for the second type of information. The second type of information may be a graphics command.
A method of the invention is provided for controlling an information recording and replaying apparatus for recording information on a storage means for storing information and replaying information from the storage means. The method comprises the steps of: having the apparatus perform at least one of an operation of recording a first type of information provided in real time on the storage means and an operation of replaying the first type of information from the storage means; and having the apparatus perform at least one of an operation of recording a second type of information other than the first type of information on the storage means and an operation of replaying the second type of information from the storage means.
According to the information recording and replaying apparatus and the method of controlling the same of the invention, not only the first type of information provided in real time but also the second type of information other than the first type of information is recorded in the same storage means or replayed from the same storage means.
Another information recording and replaying apparatus of the invention comprises: a recording and replaying means for recording data including video and/or audio data on a recording medium to which nonlinear access is allowed and for replaying the data recorded on the medium; a plurality of input/output processing means for processing the data inputted from an external source and supplying the processed data to the recording and replaying means, and for processing the data outputted from the recording and replaying means and outputting the processed data to outside the apparatus; and a graphics processing means for receiving data for indicating a type of an image to be superimposed on the video data and supplying the data to the recording and replaying means and for outputting graphics data based on the data for indicating outputted from the recording and replaying means. Time slots are each allocated to the input/output processing means and the graphics processing means, respectively, and the input/output processing means and the graphics processing means each perform the processing within the allocated time slots.
Another information recording and replaying method of the invention uses an information recording and replaying means for recording data including video and/or audio data on a recording medium to which nonlinear access is allowed and for replaying the data recorded on the medium. The method includes: a first step of supplying the data inputted from an external source to the recording and replaying means within an allocated time slot; a second step of outputting the data from the information recording and replaying means to outside the apparatus within the time slot; a third step of receiving data for indicating a type of an image to be superimposed on the video data and supplying the data to the recording and replaying means within an allocated time slot; and a fourth step of outputting the data for indicating from the recording and replaying means within the time slot, generating graphics data from the data for indicating and outputting the graphics data.
Other and further objects, features and advantages of the invention will appear more fully from the following description.